Recognizing anthropogenic modification of the subsurface in the geological record

Humankind, in its technological development, is increasingly utilizing both mineral resources from Earth's interior and developing the rock mass as a resource in itself. In this paper we review the types of anthropogenic intrusion, at different depth ranges, that can modify the physical structure and chemistry of the subsurface. Using examples from across the world, but with emphasis on the UK, and physical models of the induced modifications, we predict what kind of subsurface signatures a geologist of the future might recognize as anthropogenic, including boreholes, tunnels and caverns, waste and resource storage facilities, mineral workings and military test traces. The potential of these anthropogenic signatures to be discriminated from natural analogues is discussed against known or modelled processes of deterioration and transformation over geological timescales of millennia or longer.